This study investigates the effect of family process and structure on the clinical course of severe, disabling and life-shortening chronic illness. It centers on the family's role in the survival of its patient member. More specifically, the study explores: 1) factors which render a family vulnerable to high levels of distress in the face of chronic illness; 2) the coping strategies which these vulnerable families employ; 3) the effect of these coping strategies on patient survival. The study will observe 75 patients with end-stage renal disease (ESRD) and their families, as well as a Comparison Group of 75 patients with uncomplicated essential hypertension and their families. ESRD patients and their families are to be studied as exemplars of the impact of family factors on the medical course and survival of persons with severe disabling chronic illnesses. Each family will be assessed at yearly intervals for a minimum of three years or until death of the patient member occurs. The research design is shaped by a developmental model of the family's response to chronic illness which focuses on affective shifts in the alliances within the family over time. It is based on a preliminary study (Appendix A) which showed striking power of family variables, measuring process and structure, to predict patient survival time. The study employs current methods of assessment of family process and structure, of patient compliance with the medical regimen and of patient bonding to the dialysis treatment team.